Method for making blackbody radiation source

ABSTRACT

A method for making blackbody radiation source is provided. A blackbody radiation cavity and a carbon nanotube array located on a substrate are provided. A black lacquer layer is coated on an inner surface of the blackbody radiation cavity. A pressure is applied to the carbon nanotube array to form a carbon nanotube paper on the surface of the substrate. The carbon nanotube paper is placed on the black lacquer layer. And then the substrate is peeled off to separate carbon nanotubes in the carbon nanotube paper from the substrate and bond to the black lacquer layer, the carbon nanotubes in the carbon nanotube paper vertically aligned and forms the carbon nanotube array under forces of the substrate and the black lacquer layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims all benefits accruing under 35 U.S.C. § 119 fromChina Patent Application No. 201811298948.4, filed on Nov. 1, 2018, inthe China National Intellectual Property Administration, the contents ofwhich are hereby incorporated by reference. The application is alsorelated to copending applications entitled, “METHOD OF MAKING FIELDEMITTER”, filed on Apr. 24, 2019 application Ser. No. 16/393,282). Theapplication is also related to copending applications entitled, “METHODFOR TRANSFERRING CARBON NANOTUBE ARRAY”, filed on Apr. 17, 2019application Ser. No. 16/387,158). The application is also related tocopending applications entitled, “METHOD FOR REPAIRING SURFACE OF CARBONNANOTUBE ARRAY”, filed on Apr. 12, 2019 application Ser. No.16/382,413).

FIELD

The present disclosure relates to a method for making blackbodyradiation source.

BACKGROUND

With a rapid development of infrared remote sensing technology, theinfrared remote sensing technology is widely used in military andcivilian fields, such as earth exploration, weather forecasting, andenvironmental monitoring. However, all infrared detectors need to becalibrated by a blackbody before they can be used. The higher anemissivity of the blackbody, the higher an accuracy of a calibration ofthe infrared detector. Selecting high emissivity intracavity surfacematerials has a great significance for obtaining high performanceblackbody radiation sources.

Carbon nanotubes are the blackest material in the world. An emissivityof carbon nanotubes is 99.6%, which is far greater than the emissivityof other black surface materials, for example, an emissivity of NextelVelvet 81-21 black lacquer is only 96%. Therefore, the emissivity of theblackbody surface material including a carbon nanotube array is higherthan the emissivity of other blackbody surface materials.

Conventional blackbody radiation source including the carbon nanotubearray is prepared by directly growing the carbon nanotube array on theblackbody surface or directly transferring the carbon nanotube array tothe blackbody surface. However, the method of directly growing thecarbon nanotube array on the blackbody surface is complicated inoperation and easy to introduce impurities. The method of directlytransferring the carbon nanotube array to the blackbody surface tend todestroy the carbon nanotube array during the transfer process. Forexample, the carbon nanotubes of carbon nanotube arrays may be tilted,bent, or become entangled during the transfer process, resulting asurface of the carbon nanotube array being messy and the emissivity ofblackbody radiation source being poor.

Therefore, there is a room for improvement.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present technology will now be described, by wayof example only, with reference to the attached figures, wherein:

FIG. 1 is a flow diagram of one embodiment of a method for makingblackbody radiation source.

FIG. 2 is a process diagram of the method for making blackbody radiationsource in FIG. 1.

FIG. 3 is a scanning electron microscope (SEM) image of a carbonnanotube paper of one embodiment.

FIG. 4 is a flow diagram of one embodiment of a method for makingblackbody radiation source.

FIG. 5 is a process diagram of the method for making blackbody radiationsource in FIG. 4.

DETAILED DESCRIPTION

The disclosure is illustrated by way of example and not by way oflimitation in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that referencesto “another,” “an,” or “one” embodiment in this disclosure are notnecessarily to the same embodiment, and such references mean “at leastone.”

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein can be practiced without these specificdetails. In other instances, methods, procedures, and components havenot been described in detail so as not to obscure the related relevantfeature being described. Also, the description is not to be consideredas limiting the scope of the embodiments described herein. The drawingsare not necessarily to scale, and the proportions of certain parts havebeen exaggerated to better illustrate details and features of thepresent disclosure.

Several definitions that apply throughout this disclosure will now bepresented.

The term “substantially” is defined to be essentially conforming to theparticular dimension, shape, or other feature which is described, suchthat the component need not be exactly or strictly conforming to such afeature. The term “comprise,” when utilized, means “include, but notnecessarily limited to”; it specifically indicates open-ended inclusionor membership in the so-described combination, group, series, and thelike.

FIG. 1 and FIG. 2 illustrate a method for making blackbody radiationsource of one embodiment. The method for making blackbody radiationsource comprises:

step (S11): providing a blackbody radiation cavity 11 comprising aninner surface, a carbon nanotube array 12, and a substrate 13, thecarbon nanotube array 12 located on the substrate 13, and the carbonnanotube array 12 comprises a plurality of carbon nanotubes comprising aroot portion 122 directly contacting with the substrate 13 and a topportion 124 away from the substrate 13;

step (S12): coating a black lacquer layer 14 on the inner surface of theblackbody radiation cavity 11;

step (S13): applying a pressure on a surface of the carbon nanotubearray 12 to make the carbon nanotubes of the carbon nanotube array 12toppled over on a surface of the substrate 13 and form a carbon nanotubepaper 15 comprising the plurality of carbon nanotubes, and the pluralityof carbon nanotubes in the carbon nanotube paper 15 being parallel tothe surface of the substrate 13;

step (S14): placing the carbon nanotube paper 15 on the black lacquerlayer 14, to make the carbon nanotube paper 15 located between thesubstrate 13 and the black lacquer layer 14; and

step (S15): peeling off the substrate 13 to separate the plurality ofcarbon nanotubes in the carbon nanotube paper 15 from the substrate 13and bond to the black lacquer layer 14, the plurality of carbonnanotubes in the carbon nanotube paper 15 vertically aligned forms thecarbon nanotube array 12 under a force between the substrate 13 and theplurality of carbon nanotubes in the carbon nanotube paper 15 and aforce between the black lacquer layer 14 and the plurality of carbonnanotubes in the carbon nanotube paper 15, the carbon nanotubes of thecarbon nanotube array 12 substantially perpendicular to the surface ofthe black lacquer layer 14, and the top portion 124 of the carbonnanotubes of the carbon nanotube array 12 directly connecting with theblack lacquer layer 14.

The blackbody radiation cavity 11 is made of a material resistant tohigh temperature and having a high emissivity. The blackbody radiationcavity 11 can be made of hard aluminum material, aluminum alloy materialor oxygen-free copper.

The blackbody radiation cavity 11 comprises a blackbody cavity 111 and ablackbody cavity bottom 112. The blackbody cavity 111 and the blackbodycavity bottom 112 can be an integrally structure. The blackbody cavity111 and the blackbody cavity bottom 112 can also be two independentstructures, and the blackbody cavity bottom 112 can be pressed into orcan be screwed into the blackbody cavity 111 from an end opening of theblackbody cavity 111.

The blackbody cavity 111 comprises a room. A cross section of the roomcan be circle, ellipse, triangle, quad, or other polygon. A shape of abottom surface of the room is not limited. The shape of the bottomsurface of the room can be a flat surface, a tapered surface, aprismatic surface, or other surfaces.

In one embodiment, the inner surface of the blackbody radiation cavity11 is smooth. In one embodiment, a plurality of microstructures isformed on the inner surface of the blackbody radiation cavity 11. Theplurality of microstructures can be a plurality of grooves spacingformed on the inner surface of the blackbody radiation cavity 11. Theplurality of grooves can be annular grooves, strip grooves, pointgrooves or grooves extending axially along the blackbody radiationcavity 11.

In one embodiment, the blackbody cavity 111 and the blackbody cavitybottom 112 is an integrally structure, the blackbody cavity 111comprises a cylindrical room, and the inner surface of the blackbodyradiation cavity 11 is smooth.

In one embodiment, the carbon nanotube array 12 is a super-alignedcarbon nanotube array. The carbon nanotubes of the super-aligned carbonnanotube array are substantially parallel to each other andperpendicular to a surface of the substrate 13.

The carbon nanotubes of the super-aligned carbon nanotube array isjoined with each other by Van der Waals forces to form an array. Thecarbon nanotubes of the super-aligned carbon nanotube arraysubstantially perpendicular to the surface of the substrate 13, meaningthat a large number of the carbon nanotubes of the super-aligned carbonnanotube array are perpendicular to the surface of the substrate 13, anda minority of carbon nanotubes of the super-aligned carbon nanotubearray may be inclined. However, the number of inclined carbon nanotubesis very small and does not affect the overall oriented alignment of themajority of carbon nanotubes in the super-aligned carbon nanotube array.The inclined carbon nanotubes can be ignored. The super-aligned is freewith impurities, such as amorphous carbon, residual catalyst metalparticles or the like.

A method for making the super-aligned carbon nanotube array can be achemical vapor deposition (CVD) method, an arc discharge preparationmethod, or an aerosol preparation method. In one embodiment, thesuper-aligned carbon nanotube array is directly grown on the substrate13 by the chemical vapor deposition (CVD) method. The chemical vapordeposition (CVD) method comprises the steps of (a) forming a catalystlayer on a surface of the substrate 13, in which a material of thecatalyst layer can be selected from the group consisting of iron (Fe),cobalt (Co), nickel (Ni) and alloy of any combination thereof. Step (b)is annealing the substrate with the catalyst layer in air at 700° C. to900° C. for about 30 minutes to 90 minutes and (c) disposing thesubstrate 13 in a reaction chamber. The reaction chamber is heated inprotective gas to 500° C.-740° C., and a carbon source gas is introducedinto the reaction chamber for about 5 minutes to about 30 minutes. Aheight of the carbon nanotube of the super-aligned carbon nanotube arrayis ranged from about 200 micrometers to about 650 micrometers. Thecarbon source gas can be chemically active hydrocarbons, such asacetylene. The protective gas can be nitrogen, ammonia, or an inert gas.Examples of the method of making the super-aligned carbon nanotube arrayare taught by U.S. Pat. No. 7,045,108 to Jiang et al.

The black lacquer layer 14 has a viscosity. A bond force between theroot portions 122 of the plurality of carbon nanotubes and the blacklacquer layer 14 is less than a bond force between the top portions 124of the plurality of carbon nanotubes and the black lacquer layer 14. Thebond force between the top portions 124 of the carbon plurality ofnanotubes and the black lacquer layer 14 is greater than a bond forcebetween the root portions 122 of the plurality of carbon nanotubes andthe substrate 13.

In one embodiment, the substrate 13 is a flat structure. A material ofthe substrate 13 can be flexible or rigid. For example, the material ofthe substrate 13 can be tape, metal, glass, plastic, silicon wafer,silicon dioxide sheet, quartz sheet, polymethyl methacrylate (PMMA), orpolyethylene terephthalate (PET). In one embodiment, the substrate 13 isa silicon wafer.

The black lacquer 14 has high emissivity, such as Pyromark 1200 blacklacquer having an emissivity 0.92, Nextel Velvet 811-21 black lacquerhaving an emissivity 0.95. In one embodiment, the black lacquer layer 14is doped with a black material such as carbon nanotubes. A content ofthe carbon nanotubes in the black lacquer doped with carbon nanotubes isfrom about 1% to about 50%. In one embodiment, the material of the blacklacquer layer 14 is the Nextel Velvet 811-21 black lacquer. A thicknessof the black lacquer layer 14 can not be too small or too large. Whenthe thickness of the black lacquer layer 14 is too small, such as lessthan 1 micrometer, a bind force between the carbon nanotube array 12 andthe inner surface of the blackbody radiation cavity 11 is weak, and thecarbon nanotube array 12 cannot be firmly fixed to the inner surface ofthe black body radiation cavity 11. On the contrary, when the thicknessof the black lacquer layer 14 is too large, such as larger than 300micrometers, the carbon nanotube array 12 is embedded in the blacklacquer layer 14, therefore, a structure of the carbon nanotube array 12is destroyed, and a high emissivity of the carbon nanotube array 12cannot be exhibited. In one embodiment, the thickness of the blacklacquer layer 14 ranges from about 1 micrometer to about 300micrometers.

In step (S13), a surface of the carbon nanotube array 12 directlycontacting with the substrate 13 is defined as a first surface, asurface of the carbon nanotube array 12 away from the first surface andopposite to the first surface is defined as a second surface. The firstsurface is formed by the root portions 122 of all the carbon nanotubesin the carbon nanotube array 12, and the second surface is formed by thetop portions 124 of all the carbon nanotubes in the carbon nanotubearray 12.

Applying the pressure on the second surface of the carbon nanotube array30 by a pressure providing device. The pressure providing device can bea roller or a plate but not limited to them. When the pressure providingdevice is the roller, the roller can roll counterclockwise or clockwiseon the second surface. When the pressure providing device is the plate,an angle between a direction of applying the pressure and the secondsurface is from 0 degree to about 90 degrees. In one embodiment, theangle between the direction of applying the pressure and the secondsurface is greater than or equal to 30 degrees and less than or equal to60 degrees. The surface of the plate or roller directly contacting withthe carbon nanotube array 12 is a flat surface and is not sticky. Amaterial of the plate or roller is not limited. The material of theplate or roller can be metal such as steel and iron. The material of theplate or roller can also be non-metal such as glass, silicon plate, anddiamond. In one embodiment, applying the pressure to the second surfaceof the carbon nanotube array 12 by a glass plate, and the angle betweenthe direction of applying the pressure and the second surface is about45 degrees.

If the pressure applied to the surface of the carbon nanotube array 12is too large, the plurality of carbon nanotubes of the carbon nanotubearray 12 are easily damaged; if the pressure applied to the surface ofthe carbon nanotube array 12 is too small, the carbon nanotube paper 15can not be formed. In one embodiment, the pressure applied to thesurface of the carbon nanotube array 12 is about 20 Newton.

In one embodiment, the pressure providing device applies pressure to thecarbon nanotube array 12 in one direction, and the plurality of carbonnanotubes of the carbon nanotube array 12 are toppled over in onedirection, therefore, the plurality of carbon nanotubes in the carbonnanotube paper 15 are aligned in the same direction. It is advantageousto vertically bond the plurality of carbon nanotubes in the carbonnanotube paper 15 to the black lacquer layer 14 to form the carbonnanotube array 12 in a subsequent step. FIG. 3 shows a scanning electronmicroscope (SEM) image of one embodiment of the carbon nanotube paper15.

In step (S14), after the carbon nanotube paper 15 is placed on thesurface of the black lacquer layer 14, the substrate 13 can be furtherpressed to better bond the top portions 124 of the plurality of carbonnanotubes in the carbon nanotube paper 15 to the black lacquer layer 14.

In step (S15), the bind force between the root portions 122 of theplurality of carbon nanotubes in the carbon nanotube paper 15 and theblack lacquer layer 14 is less than the bind force between the topportions 124 of the plurality of carbon nanotubes in the carbon nanotubepaper 15 and the black lacquer layer 14. Therefore, during peeling offthe substrate 13, the plurality of carbon nanotubes in the carbonnanotube paper 15 are first pulled up vertically, the top portions 124of the plurality of carbon nanotubes is bonded to the black lacquerlayer 14, and the root portions 122 of the plurality of carbon nanotubesis bonded to the substrate 13. The bind force between the top portions124 of the plurality of carbon nanotubes and the black lacquer layer 14is greater than the bind force between the root portions 122 of theplurality of carbon nanotubes and the substrate 13. Therefore, after thesubstrate 13 is completely peeled off, the plurality of carbon nanotubesin the carbon nanotube paper 15 are separated from the substrate 13 andvertically bonded to the surface of the black lacquer layer 14 and formthe carbon nanotube array 12 on the surface of the black lacquer layer14. The top portions 124 of the plurality of carbon nanotubes aredirectly in contact with the black lacquer layer 14. That is, after thecarbon nanotube array 12 is transferred to the black lacquer layer 14,the carbon nanotube array 12 stands upside down on the surface of theblack lacquer layer 14.

In one embodiment, during peeling off the substrate 13, a peelingdirection of the substrate 13 is perpendicular to the surface of thesubstrate 13, and all the carbon nanotubes in the carbon nanotube paper15 are simultaneously separated from the substrate 13.

The carbon nanotube array 12 can be bonded to a partial region or awhole region of the inner surface of the blackbody radiation cavity 11.In one embodiment, the carbon nanotube array 12 is bonded to the innersurface of the blackbody cavity bottom 112 by the black lacquer layer14.

After the carbon nanotube array 12 is formed on the inner surface of theblackbody radiation cavity 11, the black lacquer layer 14 can be curedby natural drying. The black lacquer layer 14 is sticky; the carbonnanotube array 12 can be firmly fixed on the inner surface of theblackbody radiation cavity 11 and is not easy to fall off.

In one embodiment, an adhesive is disposed on the surface of the blacklacquer layer to bond the carbon nanotube array 12 to the inner surfaceof the blackbody radiation cavity 11 more firmly. The adhesive can be atraditional adhesive. For example, the adhesive can be polyvinylidenefluoride (PVDF), polyvinylidene fluoride or polytetrafluoroethylene(PTFE).

The plurality of carbon nanotubes of the carbon nanotube array 12 issubstantially perpendicular to the surface of the black lacquer layer14, meaning that a large number of the carbon nanotubes of the carbonnanotube array 12 are perpendicular to the surface of the black lacquerlayer 14, and a minority of carbon nanotubes of the carbon nanotubearray 12 may be inclined. However, the number of inclined carbonnanotubes is very small and does not affect the overall orientedalignment of the majority of carbon nanotubes in the carbon nanotubearray 12. The inclined carbon nanotubes can be ignored.

In one embodiment, the method for making blackbody radiation sourcefurther comprises annealing the carbon nanotube array 12 and thesubstrate 13 before step (S11) and after step (S12). Annealing thecarbon nanotube array 12 can weaken the bind force between the pluralityof carbon nanotubes in the carbon nanotube array 12 and the substrate13; therefore, during peeling off the substrate 13, the carbon nanotubearray is easily bonded to the black lacquer layer 14 and transferred tothe black lacquer layer 14. In one embodiment, annealing the carbonnanotube array 12 and the substrate 13 in oxygen for about 9 minutes, apressure of the oxygen is about 10 torr, and an annealing temperature isabout 650° C.

In one embodiment, the method for making blackbody radiation sourcefurther comprises plasma treating the root portions 122 of the pluralityof carbon nanotubes of the carbon nanotube array 12 after step (S15), toremove impurities on the surface of the carbon nanotube array 12.

In one embodiment, the method for making blackbody radiation sourcefurther comprises wrapping a heating element on an outer surface of theblackbody radiation cavity 11, and the blackbody radiation cavity 11 canbe heated in real time. In one embodiment, the heating element comprisesa carbon nanotube structure, a first electrode and a second electrode,the first electrode and the second electrode are spaced apart from eachother on a surface of the carbon nanotube structure. The carbon nanotubestructure is wrapped or wound around the outer surface of the blackbodyradiation cavity 11. The carbon nanotube structure comprises at leastone carbon nanotube film or at least one carbon nanotube wire. Thecarbon nanotube structure comprises a plurality of carbon nanotubesconnected end to end and arranged in a preferred orientation. Theplurality of carbon nanotubes of the carbon nanotube structure extendsfrom the first electrode to the second electrode.

Because the carbon nanotube structure is wrapped or wound around theouter surface of the blackbody radiation cavity 11, after the carbonnanotube structure is energized by the first electrode and the secondelectrode, the carbon nanotube structure can heat the whole blackbodyradiation cavity 11. So that a temperature field inside the blackbodyradiation cavity 11 is evenly distributed, the temperature stability anduniformity of the cavity blackbody radiation source can be improved.Since carbon nanotube has small density and light weight, using thecarbon nanotube structure as the heating element allows the cavityblackbody radiation source to have a lighter weight. Since carbonnanotubes have high electrothermal conversion efficiency and low thermalresistance, and the carbon nanotube structure has small resistance;using the carbon nanotube structure to heat the blackbody radiationcavity has the characteristics of rapid temperature rise, small thermalhysteresis and fast heat exchange rate. Carbon nanotubes have goodtoughness, and thus the cavity blackbody radiation sources using thecarbon nanotube structure as heating element have a long service life.

When the substrate 13 is a growth substrate of the carbon nanotubearray, the adhesive between the carbon nanotubes in the carbon nanotubepaper 15 and the growth substrate is weak, and the adhesive between theplurality of carbon nanotubes in the carbon nanotube paper 15 and thesubstrate 13 is much smaller than the adhesive between the plurality ofcarbon nanotubes in the carbon nanotube paper 15 and the black lacquerlayer 14. In step (S15), during peeling off the substrate 13, theadhesive is insufficient to bond one end of the carbon nanotubes in thecarbon nanotube paper 15 to the substrate 13, and the carbon nanotubepaper 15 will be entirely separated from the substrate 13 andtransferred to the surface of the black lacquer layer 14. Therefore,when the substrate 13 is the growth substrate of the carbon nanotubearray 12, the method for making blackbody radiation source furthercomprises step (S16), placing an adhesive tape on a surface of thecarbon nanotube paper 15 away from the black lacquer layer 14, and thenpeeling off the adhesive tape. Peeling off the adhesive tape can makethe plurality of carbon nanotubes in the carbon nanotube paper 15 pulledup vertically and vertically arranged on the surface of the blacklacquer layer 14 under a force between the adhesive tape and theplurality of carbon nanotubes in the carbon nanotube paper 15 and aforce between the black lacquer layer 14 and the plurality of carbonnanotubes in the carbon nanotube paper 15. The plurality of carbonnanotubes in the carbon nanotube array 12 is vertically arranged andsubstantially perpendicular to the surface of the black lacquer layer 14and forms the carbon nanotube array 12. The bond force between thecarbon nanotubes in the carbon nanotube array 12 and the adhesive tapeis less than the bond force between the carbon nanotubes in the carbonnanotube array 12 and the black lacquer layer 14; therefore, theplurality of carbon nanotubes in the carbon nanotube paper 15 are notstuck by the adhesive tape.

FIG. 4 and FIG. 5 illustrate a method for making blackbody radiationsource of one embodiment. The method for making blackbody radiationsource comprises:

step (S21): providing a panel 21 comprising a first surface and a secondsurface opposite to the first surface, a carbon nanotube array 22, and asubstrate 23, the carbon nanotube array 22 being located on thesubstrate 23, and a plurality of carbon nanotubes of the carbon nanotubearray 22 comprising a root portion 222 directly contacting with thesubstrate 23 and a top portion 224 away from the substrate 23;

step (S22): coating a black lacquer layer 24 on the first surface of thepanel 21;

step (S23): applying a pressure on a surface of the carbon nanotubearray 22 to make the carbon nanotubes of the carbon nanotube array 22toppled over on a surface of the substrate 23 and form a carbon nanotubepaper 25 comprising the plurality of carbon nanotubes, and the pluralityof carbon nanotubes in the carbon nanotube paper 25 being parallel tothe surface of the substrate 23;

step (S24): placing the carbon nanotube paper 25 on the black lacquerlayer 24, to make the carbon nanotube paper 25 located between thesubstrate 23 and the black lacquer layer 24; and

step (S25): peeling off the substrate 23 to separate the plurality ofcarbon nanotubes in the carbon nanotube paper 25 from the substrate 23and bond to the black lacquer layer 24, the plurality of carbonnanotubes in the carbon nanotube paper 25 vertically aligned forms thecarbon nanotube array 22 on the surface of the black lacquer layer 24under a force between the substrate 23 and the plurality of carbonnanotubes in the carbon nanotube paper 25 and a force between the blacklacquer layer 24 and the plurality of carbon nanotubes in the carbonnanotube paper 25, the plurality of carbon nanotubes of the carbonnanotube array 22 substantially perpendicular to the surface of theblack lacquer layer 24, and the top portion 224 of the plurality ofcarbon nanotubes of the carbon nanotube array 22 directly connectingwith the black lacquer layer 24.

The panel 21 is made of a material resistant to high temperature andhaving a high emissivity. The panel 21 can be made of hard aluminummaterial, aluminum alloy material or oxygen-free copper.

The carbon nanotube array 22 is the same as the carbon nanotube array12, the substrate 23 is the same as the substrate 13, and the blacklacquer layer 24 is the same as the black lacquer layer 14. A method forforming the carbon nanotube paper 25 in step (S23) is the same as amethod for forming the carbon nanotube paper 15 in step (S13). A methodfor peeling off the substrate 23 in step (S25) is the same as a methodfor peeling off the substrate 13 in step (S15).

In one embodiment, the method for making blackbody radiation sourcefurther comprises wrapping a heating element on the second surface ofthe panel 21, and the panel 21 can be heated in real time. The heatingelement in this embodiment is the same as the heating element wrapped onthe outer surface of the blackbody radiation cavity 11.

In one embodiment, the method for making blackbody radiation sourcefurther comprises annealing the carbon nanotube array 32 and thesubstrate 23 before step (S22) and after step (S21). Annealing thecarbon nanotube array 22 can weaken the bind force between the carbonnanotubes in the carbon nanotube array 22 and the substrate 23;therefore, during peeling off the substrate 23, the carbon nanotubearray is easily bonded to the black lacquer layer 24 and transferred tothe black lacquer layer 24.

In one embodiment, the method for making blackbody radiation sourcefurther comprises plasma treating the root portions 222 of the carbonnanotubes of the carbon nanotube array 22 after step (S25), to removeimpurities on the surface of the carbon nanotube array 22.

When the substrate 23 is a growth substrate of the carbon nanotube array22, the adhesive between the plurality of carbon nanotubes in the carbonnanotube paper 25 and the growth substrate is weak, and the adhesivebetween the plurality of carbon nanotubes in the carbon nanotube paper25 and the substrate 23 is much smaller than the adhesive between theplurality of carbon nanotubes in the carbon nanotube paper 25 and theblack lacquer layer 24. In step (S25), during peeling off the substrate23, the adhesive is insufficient to bond one end of the carbon nanotubesin the carbon nanotube paper 25 to the substrate 23, and the carbonnanotube paper 25 will be entirely separated from the substrate 23 andtransferred to the surface of the black lacquer layer 24. Therefore,when the substrate 23 is the growth substrate of the carbon nanotubearray 22, the method for making blackbody radiation source furthercomprises placing an adhesive tape on the surface of the carbon nanotubepaper 25, and then peeling off the adhesive tape after step (S25).Peeling off the adhesive tape can make the plurality of carbon nanotubesin the carbon nanotube paper 25 pulled up vertically and verticallyarranged on the surface of the black lacquer layer 24 under a forcebetween the adhesive tape and the plurality of carbon nanotubes in thecarbon nanotube paper 25 and a force between the black lacquer layer 24and the plurality of carbon nanotubes in the carbon nanotube paper 25,to form the carbon nanotube array 22 on the surface of the black lacquerlayer 24. The plurality of carbon nanotubes in the carbon nanotube array22 is vertically arranged and substantially perpendicular to the surfaceof the black lacquer layer 24. The bond force between the carbonnanotubes in the carbon nanotube array 22 and the adhesive tape is lessthan the bond force between the carbon nanotubes in the carbon nanotubearray 22 and the black lacquer layer 24; therefore, the carbon nanotubesin the carbon nanotube paper 25 are not stuck by the adhesive tape.

The method for making blackbody radiation source has many advantages.First, the method first presses the carbon nanotube array into thecarbon nanotube paper and then bonds it. Since the carbon nanotube paperhas high mechanical strength and is not easily damaged, the carbonnanotubes will not tilted, bent, and entangled together during bondingthe carbon nanotube array, thereby improving the emission efficiency ofthe surface source blackbody. Second, the plurality of carbon nanotubesin the carbon nanotube array are parallel to each other andperpendicular to the inner surface of the blackbody radiation cavity orthe surface of the surface source blackbody substrate, a gap is formedbetween adjacent carbon nanotubes of the carbon nanotube array. Whenlight is incident on the blackbody radiation cavity or the surfacesource blackbody, the light is reflected back and forth by adjacentcarbon nanotubes in the gap, outgoing light will be greatly reduced, andthus the emissivity of the surface material is further improved. Third,since the carbon nanotube paper has high mechanical strength and is noteasily damaged, pressing the carbon nanotube array into carbon nanotubepaper before storing and transporting the blackbody radiation source,after reaching the transportation destination, the carbon nanotube paperis converted into a carbon nanotube array by the above method of theinvention. Therefore, the damage to the carbon nanotube array duringstorage and transportation can be avoided. Fourth, the carbon nanotubescan be prepared by a chemical vapor deposition of carbon source gasunder high temperature conditions, and the raw materials are cheap andeasy to obtain. Fifth, the carbon nanotubes have excellent mechanicalproperties. The use of carbon nanotube array to prepare plane sourceblackbody can increase the stability of the plane source blackbody, andmake the star borne blackbody not easy to damage in harsh environments.Sixth, the method for making blackbody radiation source is simple inoperation and low in cost.

It is to be understood that the above-described embodiments are intendedto illustrate rather than limit the present disclosure. Variations maybe made to the embodiments without departing from the spirit of thepresent disclosure as claimed. Elements associated with any of the aboveembodiments are envisioned to be associated with any other embodiments.The above-described embodiments illustrate the scope of the presentdisclosure but do not restrict the scope of the present disclosure.

Depending on the embodiment, certain of the steps of a method describedmay be removed, others may be added, and the sequence of steps may bealtered. The description and the claims drawn to a method may includesome indication in reference to certain steps. However, the indicationused is only to be viewed for identification purposes and not as asuggestion as to an order for the steps.

What is claimed is:
 1. A method for making blackbody radiation sourcecomprising: step (S11): providing a blackbody radiation cavitycomprising an inner surface, a substrate, and a carbon nanotube arraylocated on the substrate, wherein the carbon nanotube array comprises aplurality of carbon nanotubes comprising a root portion contacting withthe substrate and a top portion away from the substrate; step (S12):coating a black lacquer layer on the inner surface of the blackbodyradiation cavity; step (S13): applying a pressure on a surface of thecarbon nanotube array to make the plurality of carbon nanotubes of thecarbon nanotube array toppled over on a surface of the substrate andform a carbon nanotube paper comprising the plurality of carbonnanotubes, and the plurality of carbon nanotubes in the carbon nanotubepaper being parallel to the surface of the substrate; step (S14):placing the carbon nanotube paper on the black lacquer layer, to makethe carbon nanotube paper located between the substrate and the blacklacquer layer; and step (S15): peeling off the substrate to separate theplurality of carbon nanotubes in the carbon nanotube paper from thesubstrate and bond to the black lacquer layer, the plurality of carbonnanotubes in the carbon nanotube paper vertically aligned forms thecarbon nanotube array under a force between the substrate and theplurality of carbon nanotubes in the carbon nanotube paper and a forcebetween the black lacquer layer and the plurality of carbon nanotubes inthe carbon nanotube paper, the plurality of carbon nanotubes of thecarbon nanotube array substantially perpendicular to the surface of theblack lacquer layer, and the top portion of the plurality of carbonnanotubes of the carbon nanotube array directly connecting with theblack lacquer layer.
 2. The method of claim 1, wherein the carbonnanotube array is a super-aligned carbon nanotube array, and theplurality of carbon nanotubes of the super-aligned carbon nanotube arrayare substantially parallel to each other and perpendicular to a surfaceof the substrate.
 3. The method of claim 1, wherein a bond force betweenthe root portions of the carbon nanotubes and the black lacquer layer isless than a bond force between the top portions of the carbon nanotubesand the black lacquer layer; and the bond force between the top portionsof the carbon nanotubes and the black lacquer layer is greater than abond force between the root portions of the carbon nanotubes and thesubstrate.
 4. The method of claim 1, wherein a thickness of the blacklacquer layer ranges from about 1 micrometer to about 300 micrometers.5. The method of claim 1, applying the pressure on the surface of thecarbon nanotube array by a plate, wherein an angle between a directionof applying the pressure and the surface of the carbon nanotube arrayaway ranges from about 30 degrees to about 60 degrees.
 6. The method ofclaim 1, applying the pressure on the surface of the carbon nanotubearray in one direction, wherein the carbon nanotubes of the carbonnanotube array are toppled over in one direction, the carbon nanotubesin the carbon nanotube paper are aligned in one direction.
 7. The methodof claim 1, wherein during peeling off the substrate, a peelingdirection of the substrate is perpendicular to the surface of thesubstrate, and all the carbon nanotubes in the carbon nanotube paper aresimultaneously separated from the substrate.
 8. The method of claim 1,wherein the blackbody radiation cavity comprises a blackbody cavity anda blackbody cavity bottom, and the carbon nanotube array is bonded to aninner surface of the blackbody cavity bottom by the black lacquer layer.9. The method of claim 1, further comprising a step of annealing thecarbon nanotube array and the substrate before step (S12) and after step(S11).
 10. The method of claim 1, further comprising a step of plasmatreating the root portions of the carbon nanotubes of the carbonnanotube array after step (S15).
 11. The method of claim 1, furthercomprising a step of wrapping a heating element on an outer surface ofthe blackbody radiation cavity, to make the blackbody radiation cavitybe heated in real time.
 12. The method of claim 11, wherein the heatingelement comprises a carbon nanotube structure, a first electrode and asecond electrode, the first electrode and the second electrode arespaced apart from each other on a surface of the carbon nanotubestructure.
 13. A method for making blackbody radiation source comprises:step (S21): providing a panel comprising a first surface and a secondsurface opposite to the first surface, a substrate, and a carbonnanotube array located on and directly contacting with the substrate,wherein the carbon nanotube array comprises a plurality of carbonnanotubes comprising a root portion directly contacting with thesubstrate and a top portion away from the substrate; step (S22): coatinga black lacquer layer on the first surface of the panel; step (S23):applying a pressure on a surface of the carbon nanotube array to makethe carbon nanotubes of the carbon nanotube array toppled over on asurface of the substrate and form a carbon nanotube paper comprising theplurality of carbon nanotubes, and the plurality of carbon nanotubes inthe carbon nanotube paper being parallel to the surface of thesubstrate; step (S24): placing the carbon nanotube paper on the blacklacquer layer, to make the carbon nanotube paper located between thesubstrate and the black lacquer layer; and step (S25): peeling off thesubstrate to separate the plurality of carbon nanotubes in the carbonnanotube paper from the substrate and bond to the black lacquer layer,the plurality of carbon nanotubes in the carbon nanotube papervertically aligned forms the carbon nanotube array on the surface of theblack lacquer layer under a force between the substrate and theplurality of carbon nanotubes in the carbon nanotube paper and a forcebetween the black lacquer layer and the plurality of carbon nanotubes inthe carbon nanotube paper, the plurality of carbon nanotubes of thecarbon nanotube array substantially perpendicular to the surface of theblack lacquer layer, and the top portion of the plurality of carbonnanotubes of the carbon nanotube array directly connecting with theblack lacquer layer.
 14. The method of claim 13, wherein the carbonnanotube array is a super-aligned carbon nanotube array, and carbonnanotubes of the super-aligned carbon nanotube array are substantiallyparallel to each other and perpendicular to a surface of the substrate.15. The method of claim 13, further comprising a step of annealing thecarbon nanotube array and the substrate before step (S22) and after step(S21).
 16. The method of claim 13, further comprising a step of wrappinga heating element on the second surface of the panel, to make the panelbe heated in real time.
 17. The method of claim 16, wherein the heatingelement comprises a carbon nanotube structure, a first electrode and asecond electrode, the first electrode and the second electrode arespaced apart from each other on a surface of the carbon nanotubestructure.
 18. The method of claim 13, further comprising a step ofplasma treating the root portions of the carbon nanotubes of the carbonnanotube array after step (S25).